{"id":{"repo_id":"buffalo","oai_identifier":"oai:ubir.buffalo.edu:10477/79410"},"canonical_url":"https://search.dev.ndltd.org/etd/buffalo/oai:ubir.buffalo.edu:10477/79410","repository":{"repo_id":"buffalo","name":"Buffalo","base_url":"https://ubir.buffalo.edu/oai/request"},"display":{"title":"Magneto-Optical Studies of Mn Doped II-VI Group Semiconductor Nanostructures","abstract":"Ph.D.","abstract_html":"Ph.D.","abstract_has_math":false,"creators":["Zhang, Peiyao; 0000-0001-7548-0262"],"institution":"State University of New York at Buffalo","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Petrou, Athos","Physics"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2019,"date_issued":"2019-04-04T20:32:34Z","date_published":"2019-04-04T20:32:34Z","updated_at":"2026-07-27T19:05:16Z","subjects":["condensed matter physics"],"languages":["eng"],"rights":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10477/79410","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Petrou, Athos","Physics"]},{"key":"dc:creator","label":"Author","values":["Zhang, Peiyao; 0000-0001-7548-0262"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2019-04-04T20:32:34Z","2019","2019-01-16 12:01:44"]},{"key":"dc:publisher","label":"Institution","values":["State University of New York at Buffalo"]},{"key":"dc:type","label":"Dc Type","values":["Text","Dissertation"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["condensed matter physics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/10477/79410"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Ph.D.","This dissertation is a magneto-optical study of two types of semiconductor nanostructures: 1) diluted magnetic semiconductor (DMS) quantum well (QW) and quantum dot (QD) structures and 2) thin layer transition metal dichalcogenide (TMD)/antiferromagnetic substrate van der Waals heterostructure. In both systems, by introducing magnetic ion into the system or using magnetic substrates, the magnetic properties of the systems are greatly modified, i.e., the sp-d exchange interaction between the spins of carriers and those of the magnetic ions in DMS nanostructures and the Zeeman splitting in TMD/AFM heterostructures. The structures under study allow for versatile control of quantum confinement and spin degree of freedom of carriers which make them interesting for fundamental physics studies as well as spintronics and other optoelectronics practical applications.We have used various optical experimental techniques, including continuous-wave and time-resolved magneto-photoluminescence and transmission spectroscopies to study the properties of two DMS nanostructures: 1) CdSe/CdMnS core/multi-shell nanoplatelets (NPLs) and 2) ZnTe quantum dots (QDs) embedded in (Zn,Mn)Se matrices. In CdSe/CdMnS NPL system, the sp-d exchange interaction between carrier spins and spins of the Mn2+ ions can be tailored by changing the position of the magnetic ion or the thickness of the magnetic shell layer. By increasing the carrier-Mn wavefunction overlap through wavefunction engineer, the magnetic properties are enhanced, and result in larger photoluminescence circular polarization and Zeeman splittings. The asymmetry in the emission lineshape suggests multiple recombination channels; these are further explored using time-resolved spectroscopy, from which recombination lifetimes were determined. In ZnTe/(Zn,Mn)Se QD system, by using different excitation photon energy, we have realized the control of the number of holes confined in the ZnTe QDs, the wavefunction overlap between the holes in the QD and the magnetic ions in (Zn,Mn)Se matrix and the photoluminescence peak energy red shift. The experimental observations are modelled theoretically with inclusion of the hole-hole Coulomb interaction as well as the hole-Mn exchange interaction.Magneto-reflectance spectroscopy was used to explore the magneto-optical properties of thin layer WS2/FePS3 heterostructures. Thin layer TMD has a bandgap in the visible region with unique spin-valley-layer locking properties: spin-up (down) transition only couples with σ+ (σ−) circularly polarized photons. With the application of an external magnetic field, the broken time-reversal symmetry between spin-up and spin-down states can be detected by studying reflectance spectra with different incident circular polarization. In monolayer WS2/FePS3, the Zeeman splitting resembles the intrinsic WS2 Zeeman behavior, due to the zero net magnetization of the AFM substrate. In contrast, bi- and tri-layer WS2/FePS3 samples exhibit enhanced Zeeman splitting with a saturation trend, indicating emergent ferromagnetism at the WS2/FePS3 interface. A temperature study reveals the coincidence of the Curie temperature of the emergent ferromagnetism and the temperature of the antiferromagnetic FePS3 substrate, confirming that the observed inter facial ferromagnetism originates from the FePS3 substrates."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Magneto-Optical Studies of Mn Doped II-VI Group Semiconductor Nanostructures"]}]}],"canonical_facts":{"dc:contributor":["Petrou, Athos","Physics"],"dc:creator":["Zhang, Peiyao; 0000-0001-7548-0262"],"dc:date":["2019-04-04T20:32:34Z","2019","2019-01-16 12:01:44"],"dc:description":["Ph.D.","This dissertation is a magneto-optical study of two types of semiconductor nanostructures: 1) diluted magnetic semiconductor (DMS) quantum well (QW) and quantum dot (QD) structures and 2) thin layer transition metal dichalcogenide (TMD)/antiferromagnetic substrate van der Waals heterostructure. In both systems, by introducing magnetic ion into the system or using magnetic substrates, the magnetic properties of the systems are greatly modified, i.e., the sp-d exchange interaction between the spins of carriers and those of the magnetic ions in DMS nanostructures and the Zeeman splitting in TMD/AFM heterostructures. The structures under study allow for versatile control of quantum confinement and spin degree of freedom of carriers which make them interesting for fundamental physics studies as well as spintronics and other optoelectronics practical applications.We have used various optical experimental techniques, including continuous-wave and time-resolved magneto-photoluminescence and transmission spectroscopies to study the properties of two DMS nanostructures: 1) CdSe/CdMnS core/multi-shell nanoplatelets (NPLs) and 2) ZnTe quantum dots (QDs) embedded in (Zn,Mn)Se matrices. In CdSe/CdMnS NPL system, the sp-d exchange interaction between carrier spins and spins of the Mn2+ ions can be tailored by changing the position of the magnetic ion or the thickness of the magnetic shell layer. By increasing the carrier-Mn wavefunction overlap through wavefunction engineer, the magnetic properties are enhanced, and result in larger photoluminescence circular polarization and Zeeman splittings. The asymmetry in the emission lineshape suggests multiple recombination channels; these are further explored using time-resolved spectroscopy, from which recombination lifetimes were determined. In ZnTe/(Zn,Mn)Se QD system, by using different excitation photon energy, we have realized the control of the number of holes confined in the ZnTe QDs, the wavefunction overlap between the holes in the QD and the magnetic ions in (Zn,Mn)Se matrix and the photoluminescence peak energy red shift. The experimental observations are modelled theoretically with inclusion of the hole-hole Coulomb interaction as well as the hole-Mn exchange interaction.Magneto-reflectance spectroscopy was used to explore the magneto-optical properties of thin layer WS2/FePS3 heterostructures. Thin layer TMD has a bandgap in the visible region with unique spin-valley-layer locking properties: spin-up (down) transition only couples with σ+ (σ−) circularly polarized photons. With the application of an external magnetic field, the broken time-reversal symmetry between spin-up and spin-down states can be detected by studying reflectance spectra with different incident circular polarization. In monolayer WS2/FePS3, the Zeeman splitting resembles the intrinsic WS2 Zeeman behavior, due to the zero net magnetization of the AFM substrate. In contrast, bi- and tri-layer WS2/FePS3 samples exhibit enhanced Zeeman splitting with a saturation trend, indicating emergent ferromagnetism at the WS2/FePS3 interface. A temperature study reveals the coincidence of the Curie temperature of the emergent ferromagnetism and the temperature of the antiferromagnetic FePS3 substrate, confirming that the observed inter facial ferromagnetism originates from the FePS3 substrates."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/10477/79410"],"dc:language":["eng"],"dc:publisher":["State University of New York at Buffalo"],"dc:rights":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."],"dc:subject":["condensed matter physics"],"dc:title":["Magneto-Optical Studies of Mn Doped II-VI Group Semiconductor Nanostructures"],"dc:type":["Text","Dissertation"]},"updated_at":"2026-07-27T19:05:16Z"}